Many countries have democratic governments under different constitutional forms. France, Germany, India, Ireland and Italy are constitutional republics, while Japan, Spain, the Netherlands, Canada and the United Kingdom are constitutional monarchies. The United States, Argentina, Brazil and Mexico have presidential systems. France has a semi-presidential system, whereas Australia, Canada, India, Pakistan, Italy, New Zealand, Poland, the Netherlands and the United Kingdom have parliamentary systems. The 20th century saw a period of sustained expansion of democracy, but in the 21st century, it is the predominant political system in the world.